were examined hourly by using polyacrylamide gel disc electrophoresis at pH .4'5 (the normal pH of brood food). The ages of larvae for which each jelly sample was taken were estimated in h ± 1 with the aid of larval growth curves. Each sample was adjusted to 50 ~lg total protein per electrophoretic tube. The number of protein bands in worker jelly gradually increased with larval age from 3 to a maximum of 8. This increase started at 36 ± 1 h of larval age and was completed at 76 ± 1 h. Electrophoretic protein patterns of royal jelly remained unchanged during the whole feeding period, while drone jelly showed the same increase in number of bands as worker jelly but only after 86 h of larval age. Protein patterns of worker jelly produced by field bees and worker jelly from queenless colonies with laying workers differed somewhat.

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